[tex]\begin{gathered} Sum\text{ of angles =180}\cdot(n-2) \\ n=\text{ number of sides} \\ Pentagon\text{ has 5 sides, hence} \\ n=5 \\ Sum\text{ of angles =180}\cdot(5-2) \\ Sum\text{ of angles =180}\cdot(3) \\ Sum\text{ of angles =5}40 \\ The\text{ sum of }these\text{ 5 angles is 540} \end{gathered}[/tex]